Nonwoven natural silk fabric and method for producing same

ABSTRACT

Disclosed is a sheet of nonwoven natural silk fabric, and particularly a sheet including threads and/or fibres of fibroin coated with sericin A, B and C. Also disclosed is a method for producing a nonwoven natural silk fabric, and particularly to a method including a step in which a thread of natural silk is deposited by a silkworm on a surface of a substrate.

FIELD OF THE INVENTION

The present invention relates to the field of nonwoven textiles, inparticular the field of nonwoven textiles comprising natural silk. Inparticular, the invention relates to a nonwoven natural silk textile,and more specifically to a sheet of nonwoven natural silk textile.

BACKGROUND OF INVENTION

Silk is a textile of animal origin which is used for manufacturing silkfabrics. In industry, it is generally produced by the caterpillars ofcertain moths, such as the caterpillar of Bombyx mori. Sericultureconsists of the set of operations of cultivating the mulberry tree,rearing the silkworm to obtain the cocoon, reeling the cocoon, andspinning the silk.

The silkworm produces silk proteins which are secreted in the form of asingle yarn (“filament”) comprising essentially two proteins, fibroinand sericin. Fibroin forms a fibre about which sericin will act as anatural adhesive, by fixing and protecting the fibres. This filament isused by the silkworm to suspend and then produce a cocoon wherein itwill be able to complete its growth and its transformation into a moth.

Traditional methods for manufacturing silk consist of killing thecaterpillar and destroying the cocoon. Conventionally, the cocoons areplaced in ovens from 70 to 80° C., then steeped in boiling water so thatthe sericin dissolves and softens, which makes it possible to releasethe fibroin fibre. During this step, most of the sericin present in thenatural silk of the cocoon is removed, either destroyed by the heat ordissolved and carried away by the rinsing water. This is followed by aspinning step, during which a plurality of fibroin fibres,conventionally about ten, are combined and attached to each other due tothe cooling of the remaining sericin.

Consequently, silk yarn obtained following a conventional manufacturingmethod includes a low proportion of sericin, which is weaklywater-soluble. This yarn is also formed from a plurality of fibroinfibres, and not from a single fibre as in the original filament. Fabricsmanufactured from this yarn will therefore have completely differentproperties to that of natural silk. Furthermore, this manufacturingmethod of silk involves killing the animal used to produce the cocoon.

Sericin has very specific properties, which distinguish it from fibroin.It particularly has a nutrient, antioxidant, anti-UV and antibacterialaction, in particular on the skin. Therefore, there is a need fortextiles formed from natural silk, rich in sericin, and not silkextracted by spinning a cocoon, processed and low in sericin.

Due to the presence of a large proportion of sericin in natural silk, itis difficult to envisage preparing natural silk yarns, and such yarnswould probably be unsuitable for weaving. Natural silk textiles willtherefore preferably be nonwoven textiles.

In view of the increasing attention focused on animal suffering andanimal cultivation conditions, there is also a demand for novelmanufacturing methods of silk textiles which are not manufactured byinterrupting the growth of the moth, and particularly for novel methodswhich avoid killing the caterpillar, chrysalis and/or moth.

The Applicant has conducted research on the structure of silk and thebehaviour of silkworms, which led her to design and manufacture nonwoventextiles formed from natural silk, as well as design and implement amanufacturing method of nonwoven textiles making it possible to remedythe drawbacks of the methods of the prior art.

SUMMARY

The invention therefore relates to a sheet of nonwoven silk textile,comprising yarns and/or fibres of fibroin coated with sericin A, sericinB and sericin C, the yarns or fibres comprising fibroin in a quantitybetween 70% and 80% and sericin A, sericin B and sericin C in a quantitybetween 20% and 30%, by weight with respect to the total weight of theyarn or fibre; and comprising at least one protruding border; the borderbeing located at the periphery of the sheet.

According to one embodiment, the protruding border has a thicknessbetween 0.1 and 100 mm, preferably between 0.25 and 25 mm, morepreferentially between 0.5 and 5 mm According to one embodiment, thesurface area occupied by the protruding border represents less than 10%,preferably less than 5%, more preferentially less than 1%, of the totalsurface area of said sheet. According to one embodiment, the width ofthe protruding border is between 0.002 and 12.5 mm, preferably between0.01 and 2.5 mm, more preferentially between 0.05 and 0.5 mm.

According to one embodiment, the sheet is partially or entirely of athree-dimensional shape; preferably of a convex shape.

The invention also relates to a sheet of nonwoven natural silk textile,comprising yarns and/or fibres of fibroin coated with sericin A, sericinB and sericin C, the yarns or fibres comprising fibroin in a quantitybetween 70% and 80% and sericin A, sericin B and sericin C in a quantitybetween 20% and 30%, by weight with respect to the total weight of theyarn or fibre; the sheet being partially or entirely of athree-dimensional shape; preferably of a convex shape.

According to one embodiment, the convex shape is a polyhedron such as atetrahedron, a cube, a hexahedron, an octahedron, regular dodecahedronand regular icosahedron; a cone; a sphere; a partially hollowed sphere;a hemisphere; an ovoid; a dome; or a combination thereof.

According to one embodiment, the sheet comprises at least one protrudingborder; the border being located at the periphery of the sheet.

According to one embodiment, the yarns and/or fibres further comprise aquantity of waxes between 0.4% and 0.8%, a quantity of carbohydratesbetween 1.2% and 1.6%, a quantity of inorganic compounds of about 0.7%and a quantity of pigments of about 0.2%, by weight with respect to thetotal weight of the yarn or fibre. According to one embodiment, theyarns have a length greater than 1 m, preferably greater than 100 m,more preferentially greater than 500 m, even more preferentially greaterthan 1 km. According to one embodiment, the fibres have a length between600 nm and 1 m, preferably between 600 μm and 1 mm.

According to one embodiment, the thickness of the sheet is between 0.001and 100 mm, preferably between 0.01 and 10 mm, more preferentiallybetween 0.1 and 1 mm, on a surface area corresponding to at least 90%,preferably at least 95%, more preferentially at least 99%, of its totalsurface area.

According to one embodiment, the sheet is a voile.

The invention also relates to an item comprising or being formed from atleast one sheet as described above.

According to one embodiment, the item comprises at least one substrate,each substrate being clad or covered in whole or in part with a sheet asdescribed above.

The invention also relates to a manufacturing method of a nonwovennatural silk textile, comprising the following steps: (a) rearing asilkworm; (b) taking the silkworm at a time when it secretes naturalsilk; (c) depositing it on a surface of a substrate wherein: the surfaceof the substrate does not contain rough areas with size greater than 3mm, preferably greater than 1 mm, more preferentially greater than 0.5mm, even more preferentially greater than 0.1 mm; the surface of thesubstrate does not contain recesses with width greater than 1.5 cm,preferably greater than 1 cm, more preferentially greater than 5 mm,even more preferentially greater than 1 mm; and the surface and/or thesubstrate is configured so as to restrict the progression of thesilkworm; (d) waiting the time required for the desired quantity ofnatural silk to be deposited on the surface of the substrate, or for thesilkworm to have secreted all its silk; (e) removing the silkworm fromthe nonwoven natural silk textile obtained; and (f) optionally,separating the nonwoven natural silk textile from the surface of thesubstrate.

According to one embodiment, the surface of the substrate is of atwo-dimensional shape. According to one embodiment, the surface of thesubstrate is partially or entirely of a three-dimensional shape;preferably of a convex shape. According to one embodiment, the surfaceof the substrate is an oval; a disk; a polygon such as a triangle, arectangle, a pentagon, a hexagon or an octagon; or a combinationthereof. According to one embodiment, the surface of the substrate is apolyhedron such as a tetrahedron, a cube, a hexahedron, an octahedron,regular dodecahedron and regular icosahedron; a cone; a sphere; apartially hollowed sphere; a hemisphere; an ovoid; a dome with apolyhedral base; or a combination thereof.

According to one embodiment, the surface of the substrate contains norough areas and/or no recesses. According to one embodiment, thesubstrate does not contain rough areas with size greater than 3 mm up toa distance of 1 mm, preferably 5 mm, more preferentially 25 mm, evenmore preferentially 50 mm, from the surface of the substrate. Accordingto one embodiment, the substrate does not contain recesses with widthgreater than 1.5 cm up to a distance of 1 mm, preferably 5 mm, morepreferentially 25 mm, even more preferentially 50 mm, from the surfaceof the substrate.

According to one embodiment, the nonwoven natural silk textile is asheet.

According to one embodiment, the substrate is raised, preferably bymeans of a tube, column or rod.

Definitions

In the present invention, the following terms are defined as follows:

-   -   “two-dimensional” refers to a property of a surface which is        planar, i.e. devoid of relief. A two-dimensional surface is        particularly devoid of concavity and convexity. The method        according to the invention makes it possible in particular to        obtain sheets of a two-dimensional shape.    -   “cocoon” refers to a natural silk casing produced by a silkworm        wherein it completes its transformation into a moth.    -   “concave” refers to a property of a surface which is hollow,        i.e. which has an inwardly rounded shape. The opposite thereof        is “convex” or “domed”. The concavity of an object denotes the        part thereof which has a hollow shape.    -   “convex” refers to a property of a surface which has a raised,        or domed, surface, i.e. which has an outwardly rounded shape.        The convexity of object denotes the part thereof which has a        domed shape.    -   “about” placed in front of a number denotes more or less 10% of        the nominal value of this number.    -   “thickness” refers, if the context relates to a sheet, to one of        the dimensions of the sheet, measured by the difference between        the two main faces thereof. For example, if the sheet is        comparable to a parallelepiped or a disk, the thickness thereof        is the height of the parallelepiped or of the disk. In the        invention, the thickness of a sheet will be generally        substantially less than each of the dimensions of the faces of        the sheet. Unless clearly indicated otherwise by the context,        the thickness is always measured at the centre of the faces of        the sheet.    -   “sheet” or “lap” are synonymous and refer to a piece of flat        textile including two main faces and a physical boundary        referred to as a “periphery”. A sheet may be for example a        fabric, a cloth, a material, a veil or a voile. The physical        features that may be associated with a sheet particularly        comprise the thickness thereof, perimeter thereof, surface area        thereof and density thereof. In the invention, a sheet will        generally have a thickness substantially less than each of the        dimensions of the faces thereof. For example, a sheet wherein        the faces are square-shaped may have one side having a length        greater than or equal to 5 times the thickness thereof; and a        sheet wherein the faces are disk-shaped may have a diameter        greater than or equal to 5 times the thickness thereof.    -   “fibroin” refers to a protein fibre produced by the silkworm.        Fibroin is the main constituent of natural silk.    -   “satiny” refers to a property of a surface which partially        reflects visible light so as to present a soft and slightly        glistening appearance, but which is not shiny, reflective or        luminous.    -   “sericin” refers to a protein produced by the silkworm. Sericin        is one of the main constituents of natural silk, with fibroin.        Sericin may be separated into a plurality of fractions, which        have different solubilities: sericin A is the furthest from        fibroin, sericin B is the intermediate layer and sericin C is        the inner layer adjacent to fibroin. By enabling the adhesion of        the fibroin fibres with one another, sericin acts as an adhesive        in natural silk and in the cocoon. The majority of methods of        manufacturing silk yarns or sheets according to the prior art        remove at least one type of sericin, voluntarily or        involuntarily.    -   “natural silk” or “raw silk” refer to a protein fibre produced        by a silkworm. Natural silk consists essentially of a fibre        including two strands of fibroin organised in a double helix,        joined by disulphide bridges and surrounded by successive layers        of sericin. A silkworm cocoon is essentially formed from natural        silk. When it is in the process of being secreted by the        silkworm, natural silk is also referred to as “filament”.    -   “substrate” refers to an item comprising at least one solid        surface suitable for being covered with a sheet of textile,        particularly with a sheet according to the invention.    -   “raised” refers to a state of an item, in particular of a        substrate, which is placed at a sufficient height and a        sufficient distance from any solid material such that a silkworm        deposited on the item cannot leave the item without falling. A        “raising means” refers to any means suitable for placing an item        in a raised state, i.e. rendering it raised.    -   “surface”, where it relates to a portion of a substrate, refers        to a solid surface suitable for being covered with a sheet of        textile, particularly a sheet according to the invention.    -   “textile” refers to a material which can be divided or which can        be converted into textile fibres or yarns. Examples of textiles        are silk, cotton, hemp, linen, wool, and synthetic fibres. A        woven textile is known as “woven fabric”.    -   “nonwoven textile” refers to a material of similar structure        and/or appearance to a woven fabric, but which is not woven. A        nonwoven textile is traditionally manufactured from fibres        bonded together by a chemical, mechanical and/or thermal        process. An example of nonwoven textile is felt, which is        manufactured by pressing and scalding natural fibres such as        wool.    -   “three-dimensional” refers to a property of a surface which        comprises at least one non-planar portion, i.e. which comprises        at least one relief. A three-dimensional surface may        particularly comprise a concavity and/or a convexity. The method        according to the invention makes it possible particularly to        obtain sheets of three-dimensional shape in volume such as        hemispheres or spheres.    -   “silkworm” refers to an cruciform larva (“caterpillar”), of a        moth that produces natural silk, for example Bombyx mori, the        Tussah silkworm (Antheraea pernyi), the Japanese silk moth        (Antheraea yamamai), or the ailanthus silk moth, also known as        Bombyx eri (Sarnia cynthia).    -   “voile” refers to a translucent sheet, i.e. a sheet wherein the        material allows visible light to pass, but without allowing        objects to be distinguished clearly through the sheet.

DETAILED DESCRIPTION

Sheet of Nonwoven Natural Silk Textile

The present invention relates to a sheet of nonwoven natural silktextile.

According to one embodiment, the sheet has a thickness substantiallyless than each of the dimensions of the faces thereof.

In one embodiment, the shortest of the other dimensions of the sheet isgreater than or equal to 5 times the thickness of the sheet. In onespecific embodiment, the shortest of the other dimensions of the sheetis greater than or equal to 10 times the thickness of the sheet. In onemore specific embodiment, the shortest of the other dimensions of thesheet is greater than or equal to 50 times the thickness of the sheet.In one even more specific embodiment, the shortest of the otherdimensions of the sheet is greater than or equal to 100 times thethickness of the sheet. In one even more specific embodiment, theshortest of the other dimensions of the sheet is greater than or equalto 500 times the thickness of the sheet.

According to one embodiment, the thickness of the sheet is at least 5nm, preferably at least 5 μm, more preferentially at least 0.1 mm, on asurface area corresponding to at least 90%, preferably at least 95%,more preferentially at least 99%, of its total surface area. Accordingto one embodiment, the thickness of the sheet is less than 100 mm,preferably less than 10 mm, more preferentially less than 1 mm, on asurface area corresponding to at least 90%, preferably at least 95%,more preferentially at least 99%, of its total surface area. In oneembodiment, the thickness of the sheet is between 0.001 and 100 mm,preferably between 0.01 and 10 mm, more preferentially between 0.1 and 1mm, on a surface area corresponding to at least 90%, preferably at least95%, more preferentially at least 99%, of its total surface area.

According to one embodiment, the density of the sheet is between 15 and45 g/m², preferably between 20 and 40 g/m², more preferentially between27 and 31 g/m².

According to one embodiment, the sheet is symmetrical. According to oneembodiment, the sheet is asymmetrical.

According to one embodiment, the sheet is two-dimensional. According toa further embodiment, the sheet is partially or entirely of athree-dimensional shape, such as a convexity or a concavity. In oneembodiment, the sheet is partially of a two-dimensional shape and ispartially of a three-dimension shape. According to one embodiment, thesheet comprises at least one convexity. In one embodiment, the sheet isconvex. According to one embodiment, the sheet is not concave. In oneembodiment, the sheet contains no concavity. An example of concavityaccording to the invention is a spherical shape of a diameter greaterthan or equal to 300 mm.

In one embodiment, the faces of the sheet are in the shape of an oval;disk; polygon such as a triangle, a rectangle (for example a rhombus ora square), a pentagon, a hexagon or an octagon; or the combinationsthereof.

In one specific embodiment, the faces of the sheet are rectangleswherein the width is greater than or equal to 5 times, preferably 10times, more preferentially 50 times, even more preferentially 100 times,even more preferentially 500 times, the thickness of the sheet. The“width” is defined in this context as being the shorter of the two sidesof the surface of the rectangle.

In one specific embodiment, the faces of the sheet are disks wherein thediameter is greater than or equal to 5 times, preferably 10 times, morepreferentially 50 times, even more preferentially 100 times, even morepreferentially 500 times, the thickness of the sheet.

In one embodiment, the sheet is three-dimensional and the sheet is apartially or entirely regular volume. In one specific embodiment, thesheet is a polyhedron such as a tetrahedron, a cube, a hexahedron (forexample a parallelepiped), an octahedron, regular dodecahedron andregular icosahedron; a cone, a sphere; a partially hollowed sphere, ahemisphere; an ovoid; a dome with a polyhedral base; or the combinationsthereof. In one specific embodiment, the edges of the polyhedron aremarked by the presence of a protruding border along the entire length ofthe edge.

In one specific embodiment, the sheet is a sphere or a hemispherewherein the circumference is greater than or equal to 5 times,preferably 10 times, more preferentially 50 times, even morepreferentially 100 times, even more preferentially 500 times, thethickness thereof, measured at any point of the sphere or of thehemisphere.

In one embodiment, the sheet is three-dimensional and the sheet is avolume of irregular shape, for example a flower petal or an asymmetricalshape.

In one embodiment, the sheet is three-dimensional and the sheet is avolume which forms a part of an item of clothing or an item of clothing,for example a corset.

According to one embodiment, the sheet is a voile, i.e. a translucentsheet. In one embodiment, the voile has a thickness between 0.001 and 1mm, preferably between 0.01 and 0.1 mm, more preferentially between 0.1and 0.5 mm, on a surface area corresponding to at least 90%, preferablyat least 95%, more preferentially at least 99%, of its total surfacearea. In one embodiment, the voile has a thickness of 0.1 to 0.3 mm on asurface area corresponding to at least 90% of its total surface area andits transparency is comparable, for example, to that of an organza. In afurther embodiment, the voile has a thickness of 0.3 to 0.9 mm on asurface area corresponding to at least 90% of its total surface area andits transparency is comparable, for example, to that of a silk muslin.In a further embodiment, the voile has a thickness of 1 to 1.5 mm on asurface area corresponding to at least 90% of its total surface area andits transparency is comparable, for example, to that of a silk twill. Ina further embodiment, the voile has a thickness of at least 1.6 mm on asurface area corresponding to at least 90% of its total surface area andits degree of opacity is comparable, for example, to that of a felt.According to a further embodiment, the sheet is opaque.

According to one embodiment, the sheet comprises a fabric side and aback. In one embodiment, the back has a more satin appearance than thefabric side.

According to one embodiment, the sheet comprises at least one protrudingborder. In one embodiment, the protruding border is located at theperiphery of the sheet. In one embodiment, the sheet includes a fabricside and a back and the border is protruding with respect to the fabricside of the sheet. In one embodiment, the thickness of the protrudingborder is between 0.1 and 100 mm, preferably between 0.25 and 25 mm,more preferentially between 0.5 and 5 mm. In one embodiment, the widthof the protruding border is between 0.002 and 12.5 mm preferably between0.01 and 2.5 mm, more preferentially between 0.05 and 0.5 mm. In oneembodiment, the surface area occupied by the protruding borderrepresents less than 10%, preferably less than 5%, more preferentiallyless than 1%, of the total surface area of the sheet. Advantageously,the protruding border enhances the physical properties of the sheet, forexample the resistance to deformation (rigidity). Advantageously, thepresence of the protruding border makes it possible to avoid a finishingstep such as rolling or oversewing (hem or border formation).Advantageously, the presence of the protruding border makes it possibleto avoid a finishing step such as a roundseam (immobilisation of yarnson the periphery of a fabric).

According to one embodiment, the sheet is not a cocoon. According to oneembodiment, the sheet does not comprise any material derived from acocoon. According to one embodiment, the sheet is not manufactured fromcocoons.

According to one embodiment, the sheet comprises yarns and/or fibres offibroin coated with at least one sericin. In one embodiment, the sheetcomprises yarns and/or fibres of fibroin coated with sericin A, sericinB and/or sericin C. In one specific embodiment, the sheet comprisesyarns and/or fibres of fibroin coated with sericin A, sericin B andsericin C.

According to one embodiment, the sheet comprises yarns and/or fibrescomprising fibroin in a quantity between 70% and 80% and at least onesericin in a quantity ranging between 20% and 30%, by weight withrespect to the total weight of the yarn or fibre.

In one embodiment, the sheet comprises yarns and/or fibres having thecomposition indicated in Table 1. In one embodiment, the sheet has thecomposition indicated in Table 1.

TABLE 1 Component % (weight/weight) Fibroin 70-80 Sericin 20-30 Waxes0.4-0.8 Carbohydrates 1.2-1.6 Inorganic compounds About 0.7 PigmentsAbout 0.2

According to one embodiment, the sheet comprises yarns wherein thelength is greater than 1 m, preferably greater than 100 m, morepreferentially greater than 500 m, even more preferentially greater than1 km. According to one embodiment, the sheet comprises yarns wherein thelength is less than 3 km, preferably less than 2 km. In one embodiment,the length of the yarns is greater than 1 m and less than 2 km. In onespecific embodiment, the sheet comprises yarns wherein the length isbetween 1 and 1.5 km.

According to one embodiment, the sheet comprises fibres wherein thelength is between 600 nm and 1 m, preferably between 50 μm and 1 mm.

According to one embodiment, the fibres and/or yarns have a triangularcross-section. According to one embodiment, if the cross-section thereofis equated with a circular cross-section, the fibres and/or yarns have adiameter of about 10 μm.

According to one embodiment, the yarns and/or fibres are arrangednon-randomly. According to one embodiment, the yarns and/or fibres areoriented. According to one embodiment, the yarns and/or fibres do notform a mesh.

According to one embodiment, the sheet comprises silk fibres breakingdown between 100 and 150° C., preferably at about 130° C. According toone embodiment, the sheet comprises silk fibres having a carbonisationtemperature between 250 and 350° C., preferably about 300° C. Accordingto one embodiment, the sheet comprises silk fibres having anextensibility of about 17% to about 25% dry, and about 30% wet.

The nonwoven textile sheet according to the invention may undergovarious post-treatments, and particularly finishing techniques known tothose skilled in the art. In particular, the sheet may be the subject ofpost-treatments generally applied to silk in the textile industry.

According to one embodiment, the sheet has undergone a post-treatmentstep such as a step of dyeing, printing, chemical priming (indispersion, in emulsion or in suspension, etc.), mechanical priming(fulling, napping, shearing, singeing, tentering, sanforising, etc.),coating, thermoforming, thermo-modelling (as defined hereinafter),cutting, pleating, embroidery or material overlay.

According to the present invention, the “thermo-modelling”post-treatment refers to a method comprising the following steps: (i)steeping a sheet of nonwoven textile in hot water, (ii) placing thesheet on a mould while still hot, and (iii) slightly stretching thesheet, (iv) drying the sheet. Step (i) makes it possible to slightlydissolve sericin and thus loosen the weft of the nonwoven textile. Step(ii) makes it possible to give the sheet the shape of the mould. Step(iii) makes it possible to ensure that the sheet takes the shape of themould correctly. Step (iv) may for example consist of leaving the sheetat ambient temperature until it has dried. After drying, the sheet keepsthe shape of the mould permanently. With this method, it is notnecessary to use an air evacuation system.

In one embodiment, the sheet has been treated by thermo-modelling at atemperature less than 60° C., preferably less than 50° C., morepreferentially at a temperature of 40° C. In one embodiment, the sheethas a thickness between 0.025 and 5 mm, preferably between 0.1 and 1 mm,and the sheet has been treated by thermo-modelling.

In one embodiment, the sheet has been dyed at a temperature less than60° C., preferably at a temperature less than 40° C., morepreferentially cold (about 25° C.).

According to one embodiment, the sheet has not undergone anypost-treatment resulting in the extraction, denaturing and/ordestruction of a sericin chosen among sericins A, B and/or C. In oneembodiment, the sheet has not undergone any chemical priming, mechanicalpriming and/or thermoforming post-treatment. In one embodiment, thesheet has not undergone any post-treatment.

Item

The invention also relates to an item which comprises or is formed fromat least one sheet of nonwoven natural silk textile as described above.

According to one embodiment, the item comprises at least one sheet asdescribed above. According to one embodiment, the item is formed from atleast one sheet as described above.

According to one embodiment, the item comprises at least one substrate,each substrate being clad or covered in whole or in part with a sheet asdescribed above. In one embodiment, the item comprises at least onesubstrate partially clad or covered with a sheet. In one embodiment, theitem comprises at least one substrate completely clad or covered with asheet. In one embodiment, the sheet is partially fixed to the substrate.In a further embodiment, the sheet is not fixed to the substrate. In onespecific embodiment, the substrate is placed on a raising means.

According to one embodiment, the item comprises at least two permanentlyjoined sheets of nonwoven natural silk textile. In one embodiment, thesheets are joined by means of at least one sericin. In one embodiment,the sheets are joined by means of natural silk yarns comprising fibroincoated with at least one sericin.

According to one embodiment, the item is a compartment comprising twosheets, joined on a portion of the periphery thereof by sericin, andcomprising a gap between the two sheets. In one embodiment, the twosheets have the same area. In a further embodiment, the two sheets havedifferent areas.

According to one embodiment, the item has undergone a post-treatmentintended to modify the properties or the appearance of the sheet, asdescribed above.

Manufacturing Method

The invention also relates to a manufacturing method of a nonwovennatural silk textile.

According to one embodiment, the nonwoven natural silk textile is asheet. In one embodiment, the sheet of nonwoven natural silk textile isas described above. According to a further embodiment, the nonwovennatural silk textile is not a sheet.

According to one embodiment, the invention relates to a manufacturingmethod of a nonwoven natural silk textile, comprising the followingsteps:

-   -   (a) rearing a silkworm;    -   (b) taking the silkworm at a time when it secretes natural silk;    -   (c) depositing it on a surface of a substrate,        -   wherein the surface of the substrate and the substrate do            not contain adhesion points to which the silkworm can attach            silk;        -   and            -   wherein the surface and/or the substrate contain at                least one means for restricting the progression of the                silkworm;            -   and/or            -   wherein the surface and/or the substrate are configured                so as to restrict the progression of the silkworm;    -   (d) waiting the time required for the desired quantity of        natural silk to be deposited on the surface of the substrate, or        for the silkworm to have secreted all its silk;    -   (e) removing the silkworm from the nonwoven natural silk textile        obtained.

In this context, the term “progression” refers to the movement of thesilkworm parallel with the surface of the substrate, on the surface ofthe substrate. Optionally, the method may comprise a step “(f)separating the nonwoven natural silk textile obtained from the surfaceof the substrate”.

According to one embodiment, the silkworm is the caterpillar of Bombyxmori, the Tussah silkworm (Antheraea pernyi), the Japanese silk moth(Antheraea yamamai), or the ailanthus silk moth (Sarnia cynthia). In oneembodiment, the silkworm is the caterpillar of Bombyx mori. The suitablerearing conditions for conducing the silkworm to secrete natural silkfall within the scope of conventional sericulture and are well-known tothose skilled in the art. According to one embodiment, the rearing ofthe silkworm comprises feeding same with white mulberry (Morus alba)leaves for about 30 days.

According to one embodiment, the worm will secrete silk continuouslyduring a period of a duration between 12 and 72 hours. In one typicalembodiment, the silkworm will secrete for 20 to 50 hours, for example 48hours.

According to one embodiment, a plurality of silkworms is taken anddeposited simultaneously and/or successively on the surface of thesubstrate. In one embodiment, the number of silkworms which are presentsimultaneously on the surface of a substrate is between 1 and 600,preferably between 1 and 400, more preferentially between 1 and 300silkworms per square metre of surface area.

According to one embodiment, the method is carried out at a temperaturebetween 15 and 35° C., preferably between 20 and 25° C., morepreferentially at about 22° C. According to one embodiment, the methodis carried out in homogeneous light, preferably in the absence of anylight gradient. According to one embodiment, the method is carried outunder controlled ambient humidity conditions, preferably with a humiditybetween 40% and 20%, typically with a humidity of about 30%.

Without wishing to be bound to any scientific theory, the Applicantbelieves that, once deposited on the surface of the substrate, the wormsecreting silk will seek three spatial adhesion points to suspend itsfuture cocoon, and if it succeeds, it will weave a cocoon about itselfinstead of depositing silk on the surface of the substrate. To obtain anonwoven textile and not a cocoon, it is therefore necessary to placethe silkworm under conditions preventing cocoon formation, i.e.preventing the silkworm from having access to three spatial adhesionpoints.

In the method according to the invention, this result is obtained due tothe fact that the surface of the substrate as well as the substrate donot contain any adhesion points to which the silkworm can attach silk,i.e. it is preferable that the surface of the substrate, if it comprisesone or more adhesion points, only comprises adhesion points which areall situated in the same plane, thus placing the worm under conditionswherein it cannot suspend a cocoon spatially. The substrate may compriseadhesion points but it is preferable that they be situated in the sameplane as any present on the surface and/or situated out of the reach ofthe silkworm. For example, the substrate may comprise one or a pluralityof “inaccessible” adhesion points, that the silkworm could not reachwithout falling from the substrate.

According to one embodiment, the surface of the substrate is entirely ofa two-dimensional shape. According to a further embodiment, the surfaceof the substrate is partially or entirely of a three-dimensional shape,such as a convexity. In one embodiment, the surface of the substrate ispartially of a two-dimensional shape and is partially of athree-dimensional shape.

According to one embodiment, the surface of the substrate comprises atleast one convexity. In one embodiment, the surface of the substrate isconvex. In one specific embodiment, the surface of the substrate is ahemisphere, preferentially a hemisphere wherein the convexity isoriented upwards. According to one embodiment, the surface of thesubstrate is not concave (i.e. is “non-concave”). In one embodiment, thesurface of the substrate contains no concavity. In one specificembodiment, the surface of the substrate is two-dimensional and/orconvex.

According to one embodiment, the surface of the substrate is a closedvolume. In one embodiment, the surface of the substrate is a closedvolume and devoid of edges.

According to one embodiment, an adhesion point to which the silkworm canattach silk is a rough area. In one embodiment, the surface of thesubstrate contains rough areas wherein the size is less than 3 mm,preferably less than 1 mm, more preferentially less than 0.5 mm, evenmore preferentially less than 0.1 mm. In one embodiment, the surface ofthe substrate contains rough areas wherein the size is greater than 0.05mm, preferably greater than 0.01 mm, more preferentially greater than0.005 mm, even more preferentially greater than 0.001 mm. In oneembodiment, the surface of the substrate does not contain rough areaswherein the size is greater than 3 mm, preferably does not contain roughareas wherein the size is greater than 1 mm, more preferentially doesnot contain rough areas wherein the size is greater than 0.5 mm, evenmore preferentially does not contain rough areas wherein the size isgreater than 0.1 mm. In one specific embodiment, the surface of thesubstrate is smooth, i.e. devoid of rough areas. An example of a surfacecontaining rough areas is a rough surface such as sandpaper. Such asurface may be obtained for example from a smooth surface (such asPlexiglas) by any means known to those skilled in the art, for exampleby sanding.

According to one embodiment, an adhesion point to which the silkworm canattach silk is a recess. In one embodiment, the surface of the substratecontains recesses wherein the width is less than 15 mm, preferably lessthan 10 mm, more preferentially less than 5 mm, even more preferentiallyless than 1 mm. In one embodiment, the surface of the substrate containsrecesses wherein the width is greater than 0.5 mm, preferably greaterthan 0.1 mm, more preferentially greater than 0.05 mm, even morepreferentially greater than 0.01 mm. In one embodiment, the surface ofthe substrate does not contain recesses wherein the width is greaterthan 1.5 cm, preferably does not contain recesses wherein the width isgreater than 1 cm, more preferentially does not contain recesses whereinthe width is greater than 5 mm, even more preferentially does notcontain recesses wherein the width is greater than 1 mm. In one specificembodiment, the surface of the substrate is solid, i.e. devoid ofrecesses. An example of a surface containing recesses is a poroussurface such as netting or a sponge. Such a surface may be obtained forexample from a solid surface by any means known to those skilled in theart, for example by perforation.

According to one embodiment, sericin does not adhere irreversibly to thesurface of the substrate, which makes it possible to detach the nonwoventextile therefrom without damaging the textile.

According to one embodiment, the surface is composed or formed of amaterial impervious to sericin. In one embodiment, the surface of thesubstrate is made of glass, metal, inorganic polymer such aspolysiloxanes (silicones), or organic polymer such as polystyrene (PS),poly(methyl methacrylate) (PMMA), for example Plexiglas® or Altuglas®.In one embodiment, the surface of the substrate is made of leather; ofwoven or nonwoven textile such as woven silk, cotton; or of paper suchas cardboard. According to one embodiment, the surface of the substrateis a material pervious to sericin, such as a nonwoven natural silktextile. According to one embodiment, the surface of the substrate ispartially or entirely formed of a material not exhibiting toxicity inrespect of the silkworm.

According to one embodiment, the surface of the substrate and/or thesubstrate is two-dimensional. In one embodiment, the surface of thesubstrate and/or the substrate is an oval; a disk; a polygon such as atriangle, a rectangle (for example a rhombus or a square), a pentagon, ahexagon or an octagon; or a combination thereof.

According to one embodiment, the surface of the substrate and/or thesubstrate is partially or entirely of a three-dimensional shape. In oneembodiment, the surface of the substrate and/or the substrate is apartially or entirely regular volume. In one specific embodiment, thesurface of the substrate and/or the substrate is a polyhedron such as atetrahedron, a cube, a hexahedron (for example a parallelepiped), anoctahedron, regular dodecahedron and regular icosahedron; a cone; asphere; a partially hollowed sphere; a hemisphere; an ovoid; a dome witha polyhedral base; or a combination thereof. In one embodiment, thesurface of the substrate and/or the substrate is partially or entirelythree-dimensional and is a volume of irregular shape. In one embodiment,the surface of the substrate and/or the substrate is a volume in theform of part of an item of clothing or of an item of clothing. In oneembodiment, the surface of the substrate and/or the substrate issymmetrical. In one embodiment, the surface of the substrate and/or thesubstrate is asymmetrical. According to one embodiment, the surface ofthe substrate measures at least 70 mm long and/or has at least 70 mm ofapparent diameter.

According to one embodiment, the dimensions of the surface of thesubstrate may be modified after the step of depositing natural silkyarns. In one embodiment, the dimensions of the surface are modified bymeans of a change of size of the substrate, for example byinflating-deflating, or by folding-unfolding.

According to one embodiment, the substrate does not contain, in thevicinity of the surface of the substrate, adhesion points to which thesilkworm can attach silk. In one embodiment, the substrate does notcontain adhesion points to which the silkworm can attach silk up to adistance of 1 mm, preferably 5 mm, more preferentially 25 mm, even morepreferentially 50 mm, from the surface of the substrate. In one specificembodiment, the substrate does not contain adhesion points to which thesilkworm can attach silk.

In the absence of an obstacle to the progression thereof, the silkwormwill continue to move along the surface of the substrate, and onlydeposit one yarn on the surface of the substrate. For this reason, inorder to obtain a nonwoven textile having a thickness greater than thediameter of the silk thread, it is necessary to constrain the silkwormto move along the surface of the substrate, this movement beingrestricted to the surface of the substrate.

In this method according to the invention, this result is obtained:

(i) in that the surface and/or the substrate comprises at least onemeans of restricting the progression of the silkworm; and/or

(ii) in that the surface and/or the substrate is configured so as torestrict the progression of the silkworm.

According to one embodiment, the surface and/or the substrate comprisesat least one means of restricting the progression of the silkworm.According to one embodiment, the surface and/or the substrate isconfigured so as to restrict the progression of the silkworm.

According to one embodiment, the configuration for restricting theprogression of the silkworm is that the substrate is raised, for exampleusing at least one raising means. The silkworm thus sees its progressionrestricted by encountering an empty space in front of it, and iscompelled to change direction, thus depositing its yarn once again onthe surface of the substrate.

In one embodiment, the substrate is placed and/or fixed on a raisingmeans, which is a part wherein the lateral dimensions are substantiallyreduced with respect to the lateral dimensions of the surface of thesubstrate, preferably reduced by 25%, more preferentially reduced by50%, even more preferentially reduced by at least 75%. Examples ofraising means according to this embodiment are a tube, a column or a rodattached to a base or to a shaft.

In one embodiment, the substrate is horizontally placed and/or fixed ona raising means.

In a further embodiment, the substrate comprises a horizontal portionincluding a surface, and this horizontal portion is raised by means of afurther portion of the substrate. In one specific embodiment, thehorizontal portion overhangs an elongated vertical portion wherein thelateral dimensions are substantially reduced with respect to the lateraldimensions of the surface, preferably reduced by 25%, morepreferentially reduced by 50%, even more preferentially reduced by atleast 75%. An example of raising means according to this embodiment is asupport with a flared base which is part of the substrate.

According to one embodiment, the spatial position of the substrate maybe modified during the method. In one embodiment, it is possible tochoose the surface of the substrate whereon the silkworm will depositthe silk yarn by orienting this surface such that this surface is theuppermost part of this substrate.

According to one embodiment, the product obtained from the method is anitem comprising at least one substrate, each substrate being clad orcovered in whole or in part with a sheet as described above. Accordingto one embodiment, the method does not include a step “(f) separatingthe nonwoven natural silk textile obtained from the surface of thesubstrate”.

According to one embodiment, the method comprises a step of bondingtogether at least two sheets of nonwoven natural silk textile. In oneembodiment, the parts of the sheets to be joined are moistened slightly,then are juxtaposed, then steps (a) to (e) of the method are carried outto ensure permanent bonding of the sheets with one another by means ofthe deposition of new natural silk yarns. In one specific embodiment,the sheets are joined by at least one edge. In one specific embodiment,the sheets are overlaid on all or part of the surface thereof.

The dry process, molten process and wet process are methods ofmanufacturing nonwoven textiles well-known to those skilled in the art.According to one embodiment, the nonwoven natural silk textile is notobtained by the dry process, molten process, or wet process.

The method according to the invention may optionally include one or aplurality of post-treatment steps, and particularly finishing techniquesknown to those skilled in the art. In particular, the method maycomprise post-treatment steps generally applied to silk in the textileindustry.

According to one embodiment, the post-treatment step is a step ofdyeing, printing, chemical priming (in dispersion, in emulsion or insuspension, etc.), mechanical priming (fulling, napping, shearing,singeing, tentering, sanforising, etc.), coating, thermoforming,thermo-modelling (as defined hereinafter), cutting, pleating, embroideryor material overlay.

In one embodiment, the nonwoven natural silk textile has been treated bythermo-modelling at a temperature less than 60° C., preferably less than50° C., more preferentially at a temperature of 40° C. In oneembodiment, the nonwoven natural silk textile has a thickness between0.025 and 5 mm, preferably between 0.1 and 1 mm, and the textile hasbeen treated by thermo-modelling. In one embodiment, the nonwovennatural silk textile has been dyed at a temperature less than 60° C.,preferably at a temperature less than 40° C., more preferentially cold(about 25° C.).

According to one embodiment, the nonwoven natural silk textile has notundergone any post-treatment resulting in the extraction, denaturingand/or destruction of a sericin chosen from sericins A, B and/or C. Inone embodiment, the nonwoven natural silk textile has not undergone anychemical priming, mechanical priming and/or thermoformingpost-treatment. In one embodiment, the nonwoven natural silk textile hasnot undergone any post-treatment.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1 to 4 are photographs representing examples of nonwoven naturalsilk textile sheets of two-dimensional shape according to the invention.

FIGS. 5 to 8 are photographs representing examples of sheets accordingto the invention, made of nonwoven natural silk textile having undergonea post-treatment.

FIGS. 9 to 15 and 24 are photographs representing examples of itemsaccording to the invention, comprising or being formed from at least onesheet of nonwoven natural silk textile, and/or comprising a substrateclad or covered in whole or in part with a sheet of nonwoven naturalsilk textile.

FIG. 16 is a diagram representing the different steps of a manufacturingmethod of a nonwoven natural silk textile according to the invention.

FIG. 17 is a photograph representing an example of a substrate suitablefor use in a manufacturing method of a nonwoven natural silk textileaccording to the invention.

FIGS. 18 and 19 are photographs representing silkworms during a step ofa manufacturing method of a nonwoven natural silk textile according tothe invention.

FIGS. 20 and 21 are diagrams representing particular embodiments of amanufacturing method of a nonwoven natural silk textile according to theinvention.

FIG. 22 is a diagram representing a set of substrates suitable for usein a manufacturing method of a nonwoven natural silk textile accordingto the invention.

FIGS. 23 and 25 to 30 are photographs representing examples of sheets ofnonwoven natural silk textile according to this invention, partially orentirely of a three-dimensional shape.

FIG. 31 is a photograph representing an example of a sheet of nonwovennatural silk textile according to the invention, partially of athree-dimensional shape. This sheet is in the form of clothing and hasundergone post-treatments.

EXAMPLES

The present invention will be understood more clearly in view of thefollowing examples illustrating the invention in a non-limiting manner.

Example 1: Sheets of Nonwoven Natural Silk Textile

FIGS. 1 and 2 show two sheets of nonwoven natural silk textile of atwo-dimensional shape. The sheet represented in FIG. 1 is a square sheethaving the dimensions 70 mm×70 mm×0.2 mm containing four protrudingborders of width 3 mm, giving same a thickness of 1.5 mm at theperiphery thereof. The sheet represented in FIG. 2 is a square sheet of500 mm sides and 0.5 mm in thickness containing four protruding bordersof width 3 mm giving same a thickness of 1 mm at the periphery thereof.

FIG. 3 shows sheets of nonwoven natural silk textile of atwo-dimensional shape, which are disks of diameter 70 mm and thickness0.3 mm containing a protruding border of width 3 mm giving them athickness of 1 mm at the periphery thereof (FIG. 4).

FIG. 4 shows a sheet of nonwoven natural silk textile of atwo-dimensional shape, which is a rectangle devoid of borders obtainedby cutting a sheet according to the invention, having the dimensions 60mm×100 mm×0.2 mm.

FIG. 23 shows a sheet of nonwoven natural silk textile partially of athree-dimensional shape, which is a cone with a hexagonal basecontaining a protruding border at the periphery of said base. The edgesof the cone are marked by the presence of a protruding border along theentire length of the edge.

FIG. 25 shows a sheet of nonwoven natural silk textile entirely of athree-dimensional shape, which is a dome with a rectangular basecontaining a protruding border at the periphery of the rectangle.

FIG. 26 shows a sheet of nonwoven natural silk textile entirely of athree-dimensional shape, which is an ovoid.

FIG. 27 shows a sheet of nonwoven natural silk textile entirely of athree-dimensional shape, which is a hemisphere containing a protrudingborder at the periphery of the cutting plane.

FIG. 28 shows a sheet of nonwoven natural silk textile entirely of athree-dimensional shape, which is a partially hollowed sphere.

FIG. 29 shows a sheet of nonwoven natural silk textile partially of athree-dimensional shape containing a protruding border at the peripherythereof, which is in the shape of flower petals.

FIG. 30 shows a sheet of nonwoven natural silk textile partially of athree-dimensional shape, which is an asymmetrical shape.

Example 2: Sheets of Nonwoven Natural Silk Textile after Post-Treatment

FIGS. 5 to 8 show sheets of nonwoven natural silk textile havingundergone a post-treatment step: printing (FIG. 5), thermo-modelling anddyeing (FIG. 6), stitching (FIG. 7), pearl embroidery (FIG. 8).

FIG. 31 shows a sheet of nonwoven natural silk textile partially of athree-dimensional shape, which is the form of clothing. The item ofclothing is a corset and has undergone a plurality of post-treatments:stitching a hem on the border, perforation of the border withincorporation of rings and threading of lacing.

Example 3: Items Containing or being Formed from at Least One Sheet ofNonwoven Natural Silk Textile, and/or Comprising a Substrate Clad orCovered in Whole or in Part with a Sheet of Nonwoven Natural SilkTextile

FIGS. 9 and 24 show a parallelepipedal three-dimensional item comprisingfive sheets of nonwoven natural silk textile permanently joined togetherby the edges thereof. This item was obtained by means of the methoddescribed in Example 5 as illustrated by the diagram in FIG. 20. Theperiphery of the hollowed face contains a protruding border and theedges of the parallelepiped are marked by the presence of a protrudingborder along the entire length of the edge.

FIG. 10 shows an item comprising a bowl-shaped bottom part and ahemispherical top part consisting of a sheet of nonwoven natural silktextile entirely of a three-dimensional shape. The hemisphere wasmanufactured by means of a method equivalent to that described inExample 4, wherein the substrate comprises at least one hemisphericalsurface. It could also be obtained by means of the method described inExample 6 as illustrated by the diagram in FIG. 21, followed by a stepof cutting of the resulting sphere. Associated with a candle, this itemmay serve as a candle holder. Associated with an electric circuit and abulb, this item may serve as an interior lamp.

FIG. 11 shows an item formed of sheets of nonwoven natural silk textilecut and joined to form an artificial flower. FIG. 12 shows such a flowerattached to a plastic stem.

FIG. 13 shows an item consisting of a substrate, which is a glassreceptacle, covered on the entire outer surface thereof with a sheet ofnonwoven natural silk textile. This item may serve as a candle holder,as illustrated in FIG. 14 which shows the item associated with a litcandle placed inside the receptacle.

FIG. 15 shows an item comprising a substrate which is a 7 cm diameterleather disk, which is clad on the entire surface thereof with a sheetof nonwoven natural silk textile. This substrate is thus entirelyincluded in the sheet.

Example 4: Manufacturing Method of a Nonwoven Natural Silk Textile

FIG. 16 shows the various steps of an example of a manufacturing methodof a nonwoven natural silk textile according to the invention.

Materials and Methods

Materials

The surface of the substrate used is typically of a two-dimensionalshape; or of a three-dimensional shape and convex; smooth or notcomprising rough areas wherein the size is greater than 0.1 mm; andsolid, non-concave and devoid of concavities. It is made of plastic (PS,PMMA) or glass, which are materials that are impervious to sericin. Thesubstrate and the surface thereof are in the shape of a square, disks,hemisphere or other shapes. The dimensions of the substrate are variableand at least 70 mm in length or in diameter. The silk yarn depositionsurface is formed of the entire top surface of the substrate.

The silkworm is the caterpillar of Bombyx mori. The substrate isconfigured so as to restrict the progression of the silkworm. It ishorizontally attached to a raising means, which is a rod secured in asupport, for example a rectangular support. The rod and the support maybe in any material, and are typically made of metal or wood. Any methodsuitable for attaching the substrate to the rod may be suitable,typically the attachment is carried out by means of an adhesive paper oran adhesive putty (such as Patafix®). The attachment zone of the rodwith the substrate may form an adhesion point for silk, but as said zoneis situated below the substrate, the silkworm cannot reach it andtherefore cannot form a cocoon. Examples of substrates with raisingmeans used in the method are shown in FIGS. 17, 18 and 22.

Methods

The caterpillar of Bombyx mori is fed with white mulberry (Morus alba)leaves for 30 days. The rearing of the caterpillar so that it reachesthe development stage where it secretes filament falls within the scopeof conventional sericulture, well-known to those skilled in the art. Themethod is carried out at 22° C., in homogeneous light and with anambient humidity of about 30%.

One or more silkworms are taken and deposited simultaneously on thesubstrate at a time when they secrete silk, and removed from thesubstrate when they have finished secreting all their silk. According tothe thickness sought for the sheet, the number of worms deposited isadapted. The number of silkworms deposited simultaneously on thesubstrate is dependent on the dimensions of the substrate and the silkthickness sought, but it is typically 400 worms/m², i.e. 4 worms/dm². Awaiting period then takes place for the time required for the soughtquantity of natural silk to be deposited on the surface of thesubstrate, or for the silkworm to have secreted all its silk. At thisstage, the silkworm is removed from the nonwoven natural silk textileobtained. Optionally, the nonwoven natural silk textile obtained isseparated from the surface of the substrate.

Results

Each silkworm moves along the substrate and deposits the natural silkfilament thereof on the substrate. This filament dries in a few seconds.Illustrations of this step of the method are shown in FIG. 18 and FIG.19. FIG. 19 illustrates the fact that two silkworms can deposit theirfilament simultaneously on the substrate without impeding or wrappingaround each other. As the silkworm sees the progression thereofrestricted by encountering an empty space in front of it, it iscompelled to change direction regularly, and to move along the surfaceof the substrate, this movement being restricted to the surface of thesubstrate. The silkworm thus moves to-and-fro along the substrate, thusdepositing its yarn on the entire surface of the substrate. In general,the silkworm stops before falling off the substrate. Nevertheless, itmay arise that a silkworm does not manage to stop when it arrives at theedge of the substrate, and falls off the substrate. It is then picked upand replaced on the surface of the substrate. The worm continues todeposit its filament on the substrate.

A sheet of nonwoven natural silk textile is obtained by means of thismethod. Examples of sheets obtained using the method are listed in Table2.

TABLE 2 Sheet Shape Th Silkworms Time Dimensions (mm) (mm) M (g) NSW NGTN T (h) #1 Disk 0.3 0.163 1 1 1 72 Diameter: 70 #2 Square 0.3 0.172 1 11 72 Side: 75 #3 Rectangle 0.3 4.129 12 2 24 144 Length: 420 Width: 297#4 Hemisphere 0.3 0.289 2 1 2 72 Diameter: 75 #5 Sphere 0.3 0.606 2 2 4144 Diameter: 75 #6 Square 1.2 0.688 1 5 5 150 Side: 75 Th: sheetthickness (mm) measured at centre of sheet; M: total mass of sheet (g);NSW: number of silkworms in a group of worms deposited simultaneously onthe surface; NG: number of groups of silkworms deposited on the surface;TN: total number of silkworms used for manufacturing the sheet.

The mean mass of natural silk produced by a Bombyx mori silkworm is0.172 g.

Example 5: Manufacture of Items Comprising at Least Two Sheets

According to one alternative embodiment of the method described inExample 4, an item is manufactured using the following method,represented schematically in FIG. 20.

A first sheet is manufactured according to the method described above,then this sheet is detached and a second sheet is manufactured in thesame way and left in place on the substrate. One edge of each of the twosheets is then moistened slightly, which induces partial dissolution ofsericin. The two edges are immediately placed in contact, and the dryingof the sericin holds the two sheets bonded together by one edge.

Silkworms are deposited on the substrate, and deposit silk which willpermanently join the two sheets together by the edge. It is alsopossible to bond the sheets while the manufacture of the second sheethas not yet been completed, in which case the silkworms willsimultaneously produce the second sheet and join it with the firstsheet. By repeating these steps several times, an item comprising atleast two sheets joined together permanently by natural silk isobtained.

The method represented in FIG. 20 particularly makes it possible toproduce a parallelepipedal item including five sheets of natural silkforming five faces of a parallelepiped, such as the item represented inFIG. 9.

Example 6: Manufacture of a Sheet of Spherical Three-Dimensional Shape

According to one alternative embodiment of the method described inExample 4, an item is manufactured using the following method,represented schematically in FIG. 21.

The substrate is a sphere or pseudosphere. As they move to avoidfalling, the silkworms will only deposit filament on the uppermostsurface of the substrate. When the sought natural silk thickness hasbeen deposited, the substrate is detached from the raising means andoriented such that the part not yet covered of the substrate becomes theuppermost part. It is not necessary to remove the silkworms from thesubstrate during the movement of the substrate. The silkworm(s) willcontinue to deposit their filament on the top surface of the substrate,and thus by successive movements of the substrate, it is possible tohave the entire surface of the substrate covered with natural silk. Thesheet obtained is devoid of protruding borders at the periphery thereof.

In the embodiment represented in FIG. 21, the substrate is an inflatableballoon and a reduced surface area, which is that which containsdeflation means (for example a nozzle), is not covered with naturalsilk. By actuating the deflation means, it is then possible to deflatethe substrate and extract it from the spherical or pseudo-sphericalshape.

According to a further possible embodiment, the substrate is solid andis not removed after the manufacture of the sheet. A spherical orpseudo-spherical item comprising a substrate partially or completelycovered with a sheet of natural silk is thus obtained.

Example 7: Substrate Assembly

According to an alternative embodiment of the method described inExample 4, a substrate assembly represented in FIG. 22 is used.

The substrates are configured such that a silkworm falling from itssubstrate would fall onto another substrate of the assembly, instead offalling onto the ground. This substrate assembly is advantageous as itmakes it possible to reduce the number of procedures required to keepthe silkworms on the surface of the substrate where they are to deposittheir filament. A tray is also paced underneath the substrate assembly,which makes it possible to retrieve the silkworms that have fallen fromsubstrate to substrate over the entire height of the substrate assembly.

1-25. (canceled)
 26. A sheet of nonwoven natural silk textile;comprising yarns and/or fibres of fibroin coated with sericin A, sericinB and sericin C; said yarns or fibres comprising fibroin in a quantitybetween 70% and 80% and sericin A, sericin B and sericin C in a quantitybetween 20% and 30%, by weight with respect to the total weight of theyarn or fibre; and comprising at least one protruding border located atthe periphery of said sheet.
 27. The sheet according to claim 26,wherein said protruding border has a thickness between 0.1 and 100 mmand a width between 0.002 and 12.5 mm.
 28. The sheet according to claim26, wherein the surface area occupied by said protruding borderrepresents less than 10% of the total surface area of said sheet. 29.The sheet according to claim 26, wherein said sheet is partially orentirely of a three-dimensional shape.
 30. A sheet of nonwoven naturalsilk textile; comprising yarns and/or fibres of fibroin coated withsericin A, sericin B and sericin C; said yarns or fibres comprisingfibroin in a quantity between 70% and 80% and sericin A, sericin B andsericin C in a quantity between 20% and 30%, by weight with respect tothe total weight of the yarn or fibre; said sheet being partially orentirely of a three-dimensional shape.
 31. The sheet according to claim30, wherein said sheet is partially or entirely of a convex shape. 32.The sheet according to claim 31, wherein the convex shape is apolyhedron; a cone; a sphere; a partially hollowed sphere; a hemisphere;an ovoid; a dome; or a combination thereof.
 33. An item comprising orbeing formed from at least one sheet according to claim
 26. 34. An itemcomprising or being formed from at least one sheet according to claim26, each substrate being clad or covered in whole or in part with thesheet.
 35. A manufacturing method of a nonwoven natural silk textile,comprising the following steps: (a) rearing a silkworm; (b) taking thesilkworm at a time when it secretes natural silk; (c) depositing it on asurface of a substrate wherein: the surface of the substrate does notcontain rough areas with size greater than 3 mm; the surface of thesubstrate does not contain recesses with width greater than 1.5 cm; andthe surface and/or the substrate is configured so as to restrict theprogression of the silkworm; (d) waiting the time required for thedesired quantity of natural silk to be deposited on the surface of thesubstrate, or for the silkworm to have secreted all its silk; (e)removing the silkworm from the nonwoven natural silk textile obtained;and (f) optionally, separating the nonwoven natural silk textile fromthe surface of the substrate.
 36. The manufacturing method according toclaim 35, wherein the surface of the substrate is of a two-dimensionalshape.
 37. The manufacturing method according to claim 35, wherein thesurface of the substrate is partially or entirely of a three-dimensionalshape.
 38. The manufacturing method according to claim 35, wherein thesurface of the substrate is an oval; a disk; a polygon; or a combinationthereof.
 39. The manufacturing method according to claim 35, wherein thesurface of the substrate is a polyhedron; a cone; a sphere; a partiallyhollowed sphere; a hemisphere; an ovoid; a dome with a polyhedral base;or a combination thereof.
 40. The manufacturing method according toclaim 35, wherein the surface of the substrate contains no rough areasand/or no recesses.
 41. The manufacturing method according to claim 35,wherein the nonwoven natural silk textile is a sheet.
 42. Themanufacturing method according to claim 35, wherein the substrate israised.
 43. The manufacturing method according to claim 42, wherein thesubstrate is raised by means of a tube, a column and/or a rod.
 44. Anitem comprising or being formed from at least one sheet according toclaim 30.